The research showed that only one in five voluntary sector organisations is regularly sharing image and video content through social media.

The survey found that, while the majority used text-based content on Twitter and Facebook, only 45 per cent of charities had an active presence across at least two of the image-based social networks, such as YouTube, Pinterest, Flickr and Instagram.

Aberfield highlighted international development organisation VSO as uploading only one video to YouTube in the past year despite annual income in excess of £50m. This was on the organisation's UK YouTube channel, which it has stopped using in favour of its international channel. Updates to the international channel are more regular, with 35 videos posted in the last year.

VSO's head of engagement Jackie Bee highlighted practical barriers facing the sector in producing compelling and relevant content. She said VSO had struggled to source effective video content because sending teams abroad or commissioning films locally can lead to high costs.

However, she said VSO was aiming to address this through a project called Voices for Development: 'We are trying to equip our volunteers to get their own material, providing them with equipment and media training.'

Age UK senior digital editor Rob Mansfield questioned whether more images automatically translated into more interest. 'Theoretically, if you use an image you increase engagement, but it doesn't always work like that.

'Images are very powerful, but it has to be the right image. If you get the topic right with the right image and the right story, it can work really well.'

Diabetes UK social media manager Joe Freeman said the problem was avoiding cliches: 'We upload images at events, but try to show more of what's happening behind the scenes. We need real people taking part in real events. If it comes across as stock imagery, it puts people off.'

However, the voluntary sector was criticised by Aberfield director Phil Reed over the type of images it tended to use. 'There is a lot of repurposed content and pictures of events, rather than thinking what the charity is about and how to put the message across,' he said. 'Every charity has case studies it can use.'

Aberfield surveyed 200 UK charities with annual incomes ranging from £10,000 to more than £5m.

Call for video content to make human connection

Charities should avoid 'talking heads' in favour of video content designed to engage potential supporters on an emotional level, according to Aberfield director Phil Reed.

While a large proportion of the 200 charities surveyed by Aberfield have a presence on YouTube, he suggested many should rethink the content they are uploading. 'There are lots of talking heads with executives and academics, and sometimes celebrities, but there is a lot of potential for using case studies,' he maintained. 'It is about emotional engagement and making it much more human, and that connection is lacking in a lot of cases. '

However, many charities regard images as being more important than video content.

ActionAid visual content manager Laurence Watts said: 'We use a lot of images in our social media to great effect. It's a very powerful way of attracting new supporters and motivating existing ones. We are using video, but we are hampered by bandwidth.'

Age UK senior digital editor Rob Mansfield added that video was less relevant for the charity's audience: 'We do use video content, but experience shows our audience isn't as engaged with video as other audiences. We know from research that it is not something they are as interested in.'

How I see it

Jane Moyo, head of media relations, ActionAid

Facebook and Twitter are the main means of reaching our supporters, but we experiment with everything, including Pinterest and Instagram. You have to experiment, but you have to do it in a strategic framework. These things come and go very quickly.

Jenny Barthow, online community manager, Tearfund

We find people engage a lot more with visual content. When people are bombarded with so many messages, really nice images are a way for us to stand out in the crowd. We are lucky to have a huge library of photos of our work from around the world on which to draw.

90% Proportion of charities with presence on Twitter and/or Facebook

22% Proportion of charities that are regularly sharing images and videos

77% Proportion of charities that have ever put a video on YouTube

17% Proportion of charities that have not uploaded a video to YouTube in 2013